Pembahasan BRP
| Date | Tags |
|---|---|
| Wednesday, 28 August 2024 | #Semester-5/Meteks |
Sub CMPK (pertanyaan UTS)
We have to reduce the consumption of energy and the emission of greenhouse gases. We have indirect sustainabiliyy measure with materials, such as materials that reduce weight of a car, turbine blades that allow more efficient machine, and catalists. CO2 come from the primary synthesis, suchs as scrap recycling, ore, scarcity of rare earch (lithium and copper) that is energy consuming to mine and produce.
Carbon and energy intensity have become better, but the population and gross domestic product per capita gives the market growth. Another growth factor of these markets are the green technologies:
50% and more of the worlds steel production are used in construction. With the increase of GDP, construction will still go on. The worst case scenario on global warming goes on, we will encounter increasing tides.
Many of the materials needed are actually quite rare
Some of these important and strategic materials have actually end of life recycling rates, some of the elements we need urgently for sustainable energies are not recylable. The punch line is, how do we tame 2 billion tons of metals/year.
Metal production stands for 8% of global energy/yr and uses 2.5 billion tons ore/yr. This production stands for 33% green house gas emission.
Sustainability needs quantification, here is a simple life cycle assesment
We have to calculate the inbound and outbound on each of these part to get the most efficient out of it. The quantification must go through all the product life cycle, but it makes it hard, because some of the production chain have a very carbon dioxide footprint, it is hard for company to agree on joint measures.
Pressure from the customer industries
Aluminium Can Carbon Footprint
Unintended consequences
Deep Sea Mining
Urban Mining
Enormous quantities that rare being scrapped in metal production
Sustainability
If eiffel tower built today, it will use 75% less steel with the same design. Another example is chasis on car that contains aluminum, iron, magnesium only have the weight of 270kg
Factors of loss material
Market of teel is growing
In 2016, the steel demand are 1600 Mtonnes and will grow to 2800 Mtonnes in 2050. Iron and steel making makes 8% of global CO2 emissions
Thermodynamic
Hematite -> Magnetite -> Roostite
Alternative of Process iron
Product -> electric arc furnace while exposing it to small partial pressure of hydrogen.
Flood the reaction chamber with argon and ignite the plasma in the material for one minute and test them. Put them into the oven, flood with same gas and plasma. After 30 minute, reduced pure iron from the ore, the efficiency of consumption in hydrogen is very good. If go through direct reduction, must put the iron sponge.
Metals can be burned to make fuel and recycle
The idea is to use powders of metal, combust in a chamber, get the energy, and subject these powder to reduction process and induce them again. About aluminium, that there are a very high decrepency from the primary (ore: 45 kWh/kg of metal produced) and secondary (scrap: 2.8 kWh/kg of metal produced). Aluminium alloys cannot be mixed very well. A very high burden in the aluminium industry in scrap recycling is in the sorting, and when recycling them again and again, some of the elements accumulate in the material (15 elements) which means in some packaging material that this cannot be used.
Iron is problematic because it formed brittle intermetallic phases. It can be changed bu further alloying.
Modern gadgets and turbine uses alot of alloy, in the field of alloy design, there are alot of high number of principal elements which is not sustainable.
Mass and energy can be conserved, but microstructure and properties are not conserved. Microstructure cana be rejuvenated with heat treatment.